1. Field of the Invention
The invention relates to a roller, preferably comprising two wheels and a locking device, an activating part being able to act on the locking device for releasing or locking in a position that corresponds to a directional lock and/or in a position that corresponds to a total lock, and the activating part being movable by a drive, a linear movement of a transmission part that is generated by the drive being transmitted via spring force to the activating part in order to move the activating part, and the activating part, in any case in a position corresponding to the total lock or in any case in a position corresponding to the directional lock, being in addition movable relative to the stationary transmission part into a release position, against a spring supported on the transmission part, by means of an actuating handle that is movable independently of the drive and preferably by hand so as to override the total lock or the directional lock.
2. The Prior Art
With regard to rollers of this type in general, reference is made in first instance to DE 10 2007 039 208 A1 (US 2010/0077562 A1), for example. In particular when such rollers are moved by an electric motor with regard to the directional and/or total lock, precautions have to be taken so that in the event of a motor failure, releasing is nevertheless still possible. For this purpose, an advantageous embodiment is sought for a release that is possible by manual intervention in the event of an emergency.